package com.seadragon.app.ksr.util;

import java.lang.reflect.Type;

import org.joda.time.LocalTime;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonDeserializer;
import com.google.gson.JsonElement;
import com.google.gson.JsonParseException;
import com.google.gson.JsonPrimitive;
import com.google.gson.JsonSerializationContext;
import com.google.gson.JsonSerializer;

public class CustomLocalTimeConverter implements JsonSerializer<LocalTime>, JsonDeserializer<LocalTime>
{
	  /** Format specifier */
	  private static final String PATTERN = "HH:mm";

	  /**
	   * Gson invokes this call-back method during serialization when it encounters a field of the
	   * specified type. <p>
	   *
	   * In the implementation of this call-back method, you should consider invoking
	   * {@link JsonSerializationContext#serialize(Object, Type)} method to create JsonElements for any
	   * non-trivial field of the {@code src} object. However, you should never invoke it on the
	   * {@code src} object itself since that will cause an infinite loop (Gson will call your
	   * call-back method again).
	   *
	   * @param src the object that needs to be converted to Json.
	   * @param typeOfSrc the actual type (fully genericized version) of the source object.
	   * @return a JsonElement corresponding to the specified object.
	   */
	  @Override
	  public JsonElement serialize(LocalTime src, Type typeOfSrc, JsonSerializationContext context)
	  {
	    final DateTimeFormatter fmt = DateTimeFormat.forPattern(PATTERN);
	    return new JsonPrimitive(fmt.print(src));
	  }

	  /**
	   * Gson invokes this call-back method during deserialization when it encounters a field of the
	   * specified type. <p>
	   *
	   * In the implementation of this call-back method, you should consider invoking
	   * {@link JsonDeserializationContext#deserialize(JsonElement, Type)} method to create objects
	   * for any non-trivial field of the returned object. However, you should never invoke it on the
	   * the same type passing {@code json} since that will cause an infinite loop (Gson will call your
	   * call-back method again).
	   *
	   * @param json The Json data being deserialized
	   * @param typeOfT The type of the Object to deserialize to
	   * @return a deserialized object of the specified type typeOfT which is a subclass of {@code T}
	   * @throws JsonParseException if json is not in the expected format of {@code typeOfT}
	   */
	  @Override
	  public LocalTime deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context)
	      throws JsonParseException
	  {
	    final DateTimeFormatter fmt = DateTimeFormat.forPattern(PATTERN);
	    return fmt.parseLocalTime(json.getAsString());
	  }
	}
